The internal and external radii of a hollow hemispherical vessel are 6cm and 7cm respectively. What is the total surface area (in cm²) of the vessel ?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 ie 183π .
C.S.A. = 2π R² + 2π r² + π (R² - r²)
= 2π (7² + 6²)+ π (7² - 6²)
= (170 + 13) π
= 183π